Wellcome Centre for Integrative Neuroimaging, Department of Experimental Psychology, Radcliffe Observatory Quarter, University of Oxford, United Kingdom.
Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom.
J Speech Lang Hear Res. 2021 Jul 16;64(7):2438-2452. doi: 10.1044/2021_JSLHR-20-00507. Epub 2021 Jun 22.
Purpose People who stutter (PWS) have more unstable speech motor systems than people who are typically fluent (PWTF). Here, we used real-time magnetic resonance imaging (MRI) of the vocal tract to assess variability and duration of movements of different articulators in PWS and PWTF during fluent speech production. Method The vocal tracts of 28 adults with moderate to severe stuttering and 20 PWTF were scanned using MRI while repeating simple and complex pseudowords. Midsagittal images of the vocal tract from lips to larynx were reconstructed at 33.3 frames per second. For each participant, we measured the variability and duration of movements across multiple repetitions of the pseudowords in three selected articulators: the lips, tongue body, and velum. Results PWS showed significantly greater speech movement variability than PWTF during fluent repetitions of pseudowords. The group difference was most evident for measurements of lip aperture using these stimuli, as reported previously, but here, we report that movements of the tongue body and velum were also affected during the same utterances. Variability was not affected by phonological complexity. Speech movement variability was unrelated to stuttering severity within the PWS group. PWS also showed longer speech movement durations relative to PWTF for fluent repetitions of multisyllabic pseudowords, and this group difference was even more evident as complexity increased. Conclusions Using real-time MRI of the vocal tract, we found that PWS produced more variable movements than PWTF even during fluent productions of simple pseudowords. PWS also took longer to produce multisyllabic words relative to PWTF, particularly when words were more complex. This indicates general, trait-level differences in the control of the articulators between PWS and PWTF. Supplemental Material https://doi.org/10.23641/asha.14782092.
口吃者（PWS）的言语运动系统比正常流畅者（PWTF）更不稳定。在这里，我们使用实时磁共振成像（MRI）来评估 PWS 和 PWTF 在流畅言语产生过程中不同构音器官运动的可变性和时长。
28 名中度至重度口吃者和 20 名 PWTF 的声道使用 MRI 进行扫描，同时重复简单和复杂的假词。以每秒 33.3 帧的速度重建从嘴唇到喉咙的声道中矢状图像。对于每个参与者，我们在三个选定的构音器官（嘴唇、舌体和软腭）中测量了在重复多次假词时的运动可变性和时长。
与 PWTF 相比，PWS 在流畅重复假词时表现出明显更大的言语运动可变性。与之前报道的唇开口测量结果一样，组间差异最为明显，但这里我们报告，在相同的发音中，舌体和软腭的运动也受到了影响。可变性不受语音复杂性的影响。在 PWS 组内，言语运动可变性与口吃严重程度无关。PWS 相对于 PWTF 也表现出在流畅重复多音节假词时更长的言语运动时长，而且这种组间差异随着复杂性的增加变得更加明显。
使用实时声道 MRI，我们发现 PWS 在流畅地重复简单假词时，其运动的可变性比 PWTF 更大。PWS 相对于 PWTF 也需要更长的时间来产生多音节词，尤其是当单词更复杂时。这表明 PWS 和 PWTF 之间在构音器官控制方面存在一般的、特质性的差异。
